Yang Yang, Zhang Xiaoming, Shi Wanzhong, et al. Differences of shale pore structure characteristics under different tectonic deformation in Fuling shale gas field[J]. ACTA PETROLEI SINICA, 2025, 46(3): 547-562.
Yang Yang, Zhang Xiaoming, Shi Wanzhong, et al. Differences of shale pore structure characteristics under different tectonic deformation in Fuling shale gas field[J]. ACTA PETROLEI SINICA, 2025, 46(3): 547-562. DOI: 10.7623/syxb202503005.
Differences of shale pore structure characteristics under different tectonic deformation in Fuling shale gas field
Tectonic deformation significantly affects the pore structure of shale. This study targets at the shale of Wufeng-Longmaxi formations in Well JY-C (stable tectonic region)
Well JY-D (weak tectonic deformation region)and Well JY-B (strong tectonic deformation region)in Fuling shale gas field. By using the shale samples with similar mineral compositions
organic geochemical characteristics and diagenesis
the relationship between tectonic deformation and pore structures was investigated through low-temperature gas adsorption experiment
scanning electron microscope observation and image processing. The results show as follows. (1)Tectonic deformation will promote the development of intragranular pores and micro-fractures in shale reservoirs
and cause the intergranular pores to become smaller but have more types to a certain extent. (2)Tectonic deformation will cause an increase in macropore volume and proportion
and a decrease in the mesopore volume and proportion. The stronger the tectonic deformation is
the larger the pore volume changes. The weak tectonic deformation will increase the micropore volume and proportion
while the strong tectonic deformation will decrease the micropore volume and proportion. Weak tectonic deformation has little effect on the specific surface area and its proportion of micropores
while strong tectonic deformation will reduce the specific surface area of micropores
but has little effect on proportion of the specific surface area. (3)Tectonic deformation will deform the organic pores
resulting in a reduction of the roundness
surface density
and surface porosity of organic pores. The greater the strength of tectonic deformation
the greater the reduction degree. Compared with large-size organic pores
small-size organic pores are more resistant to deformation
ROSS D J K,BUSTIN R M.The importance of shale composition and pore structure upon gas storage potential of shale gas reservoirs[J]. Marine and Petroleum Geology,2009,26(6):916-927.
WANG Ximeng,LIU Luofu,WANG Yang,et al.Comparison of the pore structures of Lower Silurian Longmaxi Formation shales with different lithofacies in the southern Sichuan Basin,China[J].Journal of Natural Gas Science and Engineering,2020,81:103419.
ZHU Hongjian,JU Yiwen,HUANG Cheng,et al.Pore structure variations across structural deformation of Silurian Longmaxi Shale:an example from the Chuandong thrust-fold belt[J].Fuel,2019,241:914-932.
LIANG Mingliang,WANG Zongxiu,GAO Li,et al.Evolution of pore structure in gas shale related to structural deformation[J].Fuel,2017,197:310-319.
XU Shang,GOU Qiyang,HAO Fang,et al.Shale pore structure characteristics of the high and low productivity wells,Jiaoshiba shale gas field,Sichuan Basin,China:dominated by lithofacies or preservation condition?[J].Marine and Petroleum Geology,2020,114:104211.
GUO Tonglou.The Fuling shale gas field—a highly productive Silurian gas shale with high thermal maturity and complex evolution history,southeastern Sichuan Basin,China[J].Interpretation,2015,3(2):SJ25-SJ34.
XI Zhaodong,TANG Shuheng,WANG Jing,et al.Formation and development of pore structure in marine-continental transitional shale from northern China across a maturation gradient:insights from gas adsorption and mercury intrusion[J].International Journal of Coal Geology,2018,200:87-102.
MA Xiao,GUO Shaobin,SHI Dishi,et al.Investigation of pore structure and fractal characteristics of marine-continental transitional shales from Longtan Formation using MICP,gas adsorption,and NMR (Guizhou,China)[J].Marine and Petroleum Geology,2019,107:555-571.
ZHU Hongjian,JU Yiwen,QI Yu,et al.Impact of tectonism on pore type and pore structure evolution in organic-rich shale:implications for gas storage and migration pathways in naturally deformed rocks[J].Fuel,2018,228:272-289.
WANG Xixin,HOU Jiagen,LI Shaohua,et al.Insight into the nanoscale pore structure of organic-rich shales in the Bakken Formation,USA[J].Journal of Petroleum Science and Engineering,2020,191:107182.
LANDERS J,GOR G Y,NEIMARK A V.Density functional theory methods for characterization of porous materials[J].Colloids and Surfaces A:Physicochemical and Engineering Aspects,2013,437:3-32.
THOMMES M,KANEKO K,NEIMARK A V,et al.Physisorption of gases,with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report)[J].Pure and Applied Chemistry,2015,87(9/10):1051-1069.
GILLESPIE P,VAN HAGEN J,WESSELS S,et al.Hierarchical kink band development in the Appalachian Plateau decollement sheet[J].AAPG Bulletin,2015,99(1):51-76.